Wikipedia
Flaccus was a cognomen of the ancient Roman plebeian family Fulvius, considered one of the most illustrious gentes of the city. Cicero and Pliny the Elder state that the family was originally from Tusculum, and that members still lived there in the 1st century.
As usual for cognomina, "Flaccus" was likely originally a nickname, probably of Marcus Fulvius Flaccus, the founder of the family. It has been variously interpreted as meaning "big ears", "flop ears", "floppy", or "fatty".
Flaccus was also a cognomen for a branch of the patrician Valerii and others.
Flaccus is a composer from the 2nd century BC, of whom little is known. He was either a freedman or a slave of one of Terence's patrons and wrote musical scores for Terence's comedies (playing or composing music was no occupation for a free citizen). Terence mentions him specifically in the opening didascalia to each of his comedies, and in addition mentions the type of double reed pipe to be used in each. Some further commentary on the musical modes employed has puzzled scholars: it is not known whether Terence refers to melodies or musical metres.
Flaccus has the distinction of being the only composer of Ancient Rome of whom any music is alleged to remain. A musical phrase accompanying a single line of Terence's play Hecyra was copied in the 18th century by Italian composer Arcangelo Corelli from a 10th-century manuscript; however, musicologist Thomas J. Mathiesen comments that it is no longer believed to be authentic.